diff --git a/apps/desktop/src/features/score/ScoreView.accessibility.test.tsx b/apps/desktop/src/features/score/ScoreView.accessibility.test.tsx
new file mode 100644
index 00000000..b960456c
--- /dev/null
+++ b/apps/desktop/src/features/score/ScoreView.accessibility.test.tsx
@@ -0,0 +1,69 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import type { RehearsalSong } from "@bandscope/shared-types";
+import { ScoreView } from "./ScoreView";
+
+vi.mock("@tauri-apps/api/core", () => ({
+  invoke: vi.fn()
+}));
+
+vi.mock("./ScoreViewer", () => ({
+  ScoreViewer: () => <div data-testid="score-viewer" />
+}));
+
+vi.mock("../../i18n", () => ({
+  createTranslator: () => (key: string) =>
+    ({
+      scoreViewTitle: "Score",
+      scoreViewSubtitle: "Attach validated PDF scores to the current song.",
+      scoreListTitle: "Attached scores",
+      scoreAttach: "Add score",
+      scoreRemove: "Remove",
+      scoreOpen: "Open score",
+      scoreRequiresProject: "Scores attach to the active analysis project.",
+      scoreNavDisabledHint: "Analyze or open a song first"
+    })[key] ?? key,
+  detectPreferredLocale: () => "en"
+}));
+
+const song = {
+  id: "song-a11y",
+  title: "Accessible Set",
+  sections: [],
+  exportSummary: { format: "cue-sheet", headline: "", focusSections: [] },
+  scoreAttachments: [
+    {
+      id: "score-a11y",
+      fileName: "opener.pdf"
+    }
+  ]
+} as RehearsalSong;
+
+describe("ScoreView disabled-score accessibility", () => {
+  it("references the visible disabled reason from each unavailable score button", () => {
+    render(<ScoreView song={song} projectId={null} onSongUpdate={vi.fn()} />);
+
+    const reason = screen.getByText("Scores attach to the active analysis project.");
+    const openButton = screen.getByRole("button", { name: "Open score: opener.pdf" });
+    const descriptionId = openButton.getAttribute("aria-describedby");
+
+    expect(openButton).toHaveAttribute("aria-disabled", "true");
+    expect(openButton).toHaveAttribute("title", "Analyze or open a song first");
+    expect(descriptionId).toBe(reason.id);
+    expect(descriptionId).not.toBe("");
+    expect(document.getElementById(descriptionId ?? "")).toBe(reason);
+  });
+
+  it("removes disabled-only semantics when a project workspace is available", () => {
+    render(<ScoreView song={song} projectId="project-a11y" onSongUpdate={vi.fn()} />);
+
+    const openButton = screen.getByRole("button", { name: "Open score: opener.pdf" });
+
+    expect(openButton).not.toHaveAttribute("aria-disabled");
+    expect(openButton).not.toHaveAttribute("aria-describedby");
+    expect(openButton).not.toHaveAttribute("title");
+    expect(
+      screen.queryByText("Scores attach to the active analysis project.")
+    ).not.toBeInTheDocument();
+  });
+});
diff --git a/apps/desktop/src/features/score/ScoreView.test.tsx b/apps/desktop/src/features/score/ScoreView.test.tsx
index de4ccb95..4c432e7f 100644
--- a/apps/desktop/src/features/score/ScoreView.test.tsx
+++ b/apps/desktop/src/features/score/ScoreView.test.tsx
@@ -96,7 +96,7 @@ describe("ScoreView", () => {
 
     expect(screen.getByText("Scores attach to the active analysis project.")).toBeInTheDocument();
     expect(screen.getByRole("button", { name: "Add score" })).toBeDisabled();
-    expect(screen.getByRole("button", { name: "Open score: opener.pdf" })).toBeDisabled();
+    expect(screen.getByRole("button", { name: "Open score: opener.pdf" })).toHaveAttribute("aria-disabled", "true");
     expect(screen.getByRole("button", { name: "Remove: opener.pdf" })).toBeDisabled();
 
     fireEvent.click(screen.getByRole("button", { name: "Open score: opener.pdf" }));
@@ -180,6 +180,16 @@ describe("ScoreView", () => {
     });
   });
 
+  it("renders disabled score open buttons with aria-disabled and a tooltip when there is no projectId", () => {
+    const song = makeSong([{ id: SCORE_ID, fileName: "opener.pdf" }]);
+    render(<ScoreView song={song} projectId="" onSongUpdate={vi.fn()} />);
+
+    const button = screen.getByRole("button", { name: "Open score: opener.pdf" });
+    expect(button).toHaveAttribute("aria-disabled", "true");
+    expect(button).toHaveAttribute("title", "scoreNavDisabledHint");
+    expect(button).not.toBeDisabled();
+  });
+
   it("accepts Uint8Array read responses from the bridge", async () => {
     mockInvoke.mockResolvedValueOnce(new Uint8Array([7, 7]));
     const song = makeSong([{ id: SCORE_ID, fileName: "opener.pdf" }]);
diff --git a/apps/desktop/src/features/score/ScoreView.tsx b/apps/desktop/src/features/score/ScoreView.tsx
index 72732450..a5605afb 100644
--- a/apps/desktop/src/features/score/ScoreView.tsx
+++ b/apps/desktop/src/features/score/ScoreView.tsx
@@ -1,4 +1,4 @@
-import { useMemo, useRef, useState } from "react";
+import { useId, useMemo, useRef, useState } from "react";
 import { FileMusic, FilePlus2, Loader2, Trash2 } from "lucide-react";
 import type { RehearsalSong, ScoreAttachment } from "@bandscope/shared-types";
 import { createTranslator, detectPreferredLocale } from "../../i18n";
@@ -39,6 +39,7 @@ function bridgeErrorDetail(error: unknown, fallback: string): string {
  */
 export function ScoreView({ song, projectId, onSongUpdate }: ScoreViewProps) {
   const t = useMemo(() => createTranslator(detectPreferredLocale()), []);
+  const scoreRequiresProjectId = useId();
   const attachments = useMemo(() => song.scoreAttachments ?? [], [song.scoreAttachments]);
   const [selected, setSelected] = useState<ScoreAttachment | null>(null);
   const [pdfBytes, setPdfBytes] = useState<Uint8Array | null>(null);
@@ -149,7 +150,10 @@ export function ScoreView({ song, projectId, onSongUpdate }: ScoreViewProps) {
           </div>
 
           {!projectId && (
-            <p className="rounded-xl border border-amber-300/25 bg-amber-300/10 px-4 py-3 text-sm font-medium text-amber-100">
+            <p
+              id={scoreRequiresProjectId}
+              className="rounded-xl border border-amber-300/25 bg-amber-300/10 px-4 py-3 text-sm font-medium text-amber-100"
+            >
               {t("scoreRequiresProject")}
             </p>
           )}
@@ -184,10 +188,12 @@ export function ScoreView({ song, projectId, onSongUpdate }: ScoreViewProps) {
                     <button
                       type="button"
                       onClick={projectId ? () => void openAttachment(projectId, attachment) : undefined}
-                      disabled={!projectId}
+                      aria-disabled={!projectId ? true : undefined}
+                      aria-describedby={!projectId ? scoreRequiresProjectId : undefined}
+                      title={!projectId ? t("scoreNavDisabledHint") : undefined}
                       aria-current={selected?.id === attachment.id ? "true" : undefined}
                       aria-label={`${t("scoreOpen")}: ${attachment.fileName}`}
-                      className="flex min-h-10 min-w-0 flex-1 items-center gap-2 text-left text-sm font-semibold text-slate-100 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300 disabled:cursor-not-allowed disabled:opacity-60"
+                      className="flex min-h-10 min-w-0 flex-1 items-center gap-2 text-left text-sm font-semibold text-slate-100 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300 aria-disabled:cursor-not-allowed aria-disabled:opacity-60"
                     >
                       <FileMusic className="size-4 shrink-0 text-cyan-300" aria-hidden="true" />
                       <span className="truncate">{attachment.fileName}</span>